All medical instruments that come in contact with bodily fluids, such as blood, during medical procedures must be carefully disinfected to prevent harmful contamination. There are several types of disinfectants that are used to sterilize the medical instruments.
One of the common sterilization techniques used for medical devices is steam sterilization or autoclaving. This technique sterilizes medical equipment by subjecting it to high pressure steam at 121° C. or more, typically for 15 to 20 minutes depending on the size of the medical device. Typically, autoclave system includes a vacuum pump that mechanically removes the air in the sterilizer, allowing it to be more quickly replaced with saturated steam. When the steam has displaced the air, the temperature and steam pressure build until the operating temperature is reached. This operating temperature, the temperature at which sterilization occurs, is maintained for the remainder of the cycle time.
However, autoclave sterilization systems are not suitable for disinfection of heat sensitive medical devices because such devices can be destroyed or have their useful lives severely curtailed by the high temperature and pressures associated with the steam autoclave. The heat sensitive medical devices, therefore, are commonly disinfected using liquid high level disinfectants rather than the cheaper and efficient method of steam autoclaving. The two main categories of such heat sensitive instruments are endoscopes and intracavity ultrasound probes.
Endoscopes are typically disinfected in automated washing machines that disinfect and rinse the endoscopes. There are several known automated washing machines marketed by different companies.
There are several kinds of intracavity ultrasound systems that have become increasingly popular due to their efficacy in providing useful medical information in a reasonably non-invasive manner. One of such ultrasound systems is a transvaginal ultrasound that uses an internal probe, or transducer, that enters the vaginal cavity. An internal probe allows for closer access to the structures that need evaluation. With closer access, higher frequency sound waves can be used, which provides a clearer image due to better resolution. This technique is often used to evaluate suspected cancer or abnormal growths in the female reproductive system.
Another type of intracavity ultrasound that has become increasingly popular is an endorectal ultrasound, also called transrectal ultrasound. The endorectal ultrasound is a special ultrasound technique in which the transducer is directly inserted through the anus and into the patient's rectum. The sound wave echoes detected by the transducer are converted by a computer into an image.
Both vaginal and rectal ultrasound probes are examples of heat sensitive medical instruments that cannot be steam autoclaved. The current state of the art in disinfecting such probes is to manually place an ultrasound probe into a container filled with a high level disinfectant for a certain period of time, usually specified by a manufacturer of the disinfectant. This is then followed by several fresh water rinses to remove the high level disinfectant residue from the probe.
One of such systems is described in U.S. Pat. No. 6,132,691 to Coles. This patent discloses a manual station for disinfecting intracavity ultrasound probes, such as vaginal and rectal ultrasound probes. The station includes housing and at least two containers replaceably positioned in the housing and contain a disinfectant and a rinsing agent. The ultrasonic probes are manually placed in the container with the disinfectant for soaking, and then in the container with the rinsing agent for rinsing.
However, there are a number of problems associated with known disinfecting systems for intracavity ultrasound probes. For example, one disadvantage of known systems is that the disinfecting process must be performed by an operator. The operator's variation in the performance of the process, such as mixing of the disinfectant solution, timing and equipment handling, raises problems of assurance and reproducibility of the manual disinfection process. Another disadvantage is that the system operator typically receives a prolonged exposure to harmful disinfectant fumes due to the time-consuming steps involved with the manual disinfection of the ultrasound probes. Yet another disadvantage of this known system is that it utilizes a single-use disinfectant solution, which has to be discarded after each disinfection procedure, which renders the procedure very expensive and inefficient.
What is desired, therefore, is an improved disinfectant system for intracavity ultrasound probes that overcomes the problems associated with known disinfectant systems. What is also desired is a disinfectant system for intracavity ultrasound probes that does not require manual operation by an operator thereby reducing harmful exposure to disinfectant fumes. What is further desired is a disinfectant system for intracavity ultrasound probes that is fully automated and thus more accurate. What is also desired is a disinfectant system for intracavity ultrasound probes that is capable of reusing the disinfectant solution thereby allowing for more a efficient and less costly disinfection procedure.